Method of controlling aquatic weeds

Abstract

A method of controlling aquatic weeds which comprises adding to a body of water containing the aquatic weeds a substituted 1-thiadiazolyl-3-arylurea in sufficient quantity to kill the weeds.

I claim: 
     
       1. A method of destroying aquatic weeds in water which comprises contacting the weeds with an herbicidally-effective amount of a compound of the formula ##SPC2## wherein   R is halo(C.sub. 1 -C 2 )alkyl, phenyl, nitro, hexylthio, hexylsulfonyl, or halo;   Ar is phenyl, or phenyl having one or more substituents, up to five, selected from the group consisting of methyl, nitro, trifluoromethyl, methoxy, cyano, and halo; and   X is oxygen.   
     
     
       2. The method of claim 1 wherein the active compound is 1-(3,4-dichlorophenyl)-3-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)urea. 
     
     
       3. The method of claim 1 wherein the active compound is 1-(3-chloro-4-fluorophenyl)-3-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)urea. 
     
     
       4. The method of claim 1 wherein the active compound is 1-(5-chloro-1,3,4-thiadiazol-2-yl)-3-(3,4-dichlorophenyl)urea. 
     
     
       5. The method of claim 1 wherein the active compound is 1-(3,5-dichlorophenyl)-3-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)urea. 
     
     
       6. The method of claim 1 wherein the active compound is 1-(m-tolyl)-3-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)urea. 
     
     
       7. The method of claim 1 wherein the active compound is 1-(pentachlorophenyl)-3-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)urea. 
     
     
       8. The method of claim 1 wherein the active compound is 1-(3,4-dichlorophenyl)-3-[5-(pentafluoroethyl)-1,3,4-thiadiazol-2-yl]urea. 
     
     
       9. The method of claim 1 wherein the active compound is added to said water in an amount sufficient to give a concentration of from about 1 to about 10 parts per million parts of said water.